Added CI

.gitlab-ci.yml

+variables:
+  GIT_CLEAN_FLAGS: none
+  CMAKE_CXX_FLAGS: "-Werror"
+  CMAKE_C_FLAGS: "-Werror"
+
+stages:
+  - build-entities
+  - checks
+
+default:
+  image: espressif/idf:release-v4.4
+
+build-entities:
+  stage: build-entities
+  script:
+    - cd $ENTITY
+    - echo $TERM
+    - pwd
+    - idf.py build
+  parallel:
+    matrix:
+      - ENTITY: branch
+      - ENTITY: data_center
+      - ENTITY: ec_station
+      - ENTITY: factory
+      - ENTITY: hospital
+      - ENTITY: house
+      - ENTITY: power_plant
+      - ENTITY: skyscraper
+      - ENTITY: solar_farm
+      - ENTITY: stadium
+      - ENTITY: substation
+      - ENTITY: supermarket
+      - ENTITY: wind_farm
+
+fmt:
+  image: xianpengshen/clang-tools:13
+  stage: checks
+  script:
+    - find \( -name \*.c -o -name \*.h \) ! -path ".git" ! -path '*/build/*' -print0 | xargs -0 -n 1 clang-format --Werror -n -fcolor-diagnostics
+  needs: []
+  allow_failure: true